In centrosymmetric heavy-fermion (HF) superconductors Cooper pairs have either singlet or triplet symmetry. Recently a handful of non-centrosymmetric Ce-based HF compounds have been reported to exhibit superconductivity (SC) in which the pairing wave functions have mixed symmetry. For example at ambient pressure (AP) CeCoSi3 shows SC at 1.3 K, while CeRhSi3 and CeIrSi3 show AFM ordering at 1.5 K and 5 K, respectively, but reveal SC in an applied pressure at 0.45-1.1 K at 0.4-2.3 GPa and 0.5-1.6 K at 1.8-2.5 GPa, respectively. The high value of Tc of CeIrSi3 has been attributed to the existence of strong AFM spin fluctuations, through 29Si NMR. These features resemble those of unconventional superconductors, which exhibit SC in the vicinity of a quantum critical point. We therefore propose to investigate in detail the low energy spin dynamics using musr on CeTSi3 (T=Co, Rh and Ir) at AP.